JPH08336855A - Manufacture of substrate for transparent touch panel - Google Patents

Abstract

PURPOSE: To manufacture at a single stroke a substrate for a transparent touch panel having an insulating spacer with a same material by a method wherein transparent resin is molded by injection in a mold for a transparent touch panel substrate to which a recess part for the insulating spacer is provided. CONSTITUTION: A mold cavity 1 for a transparent touch panel is equipped with a fine irregularity 2 for preventing Newton's ring, a recess part 3 for an insulating spacer, and four pieces of core pins 6 on its inner surface. The mold is set at a tip of an injection molding machine, polymethacrylate pellet being dry transparent resin is fed to a hopper of the molding machine, and molded by injection. Thereby, a polymethacrylate-made non-touch side substrate 9 is equipped with a fine irregularity 10 for preventing Newton's ring, a projection 10 for the insulating spacer, and four holes 14, 16, 18, 20 for drawing out an electrode which are shaped at once by molding on its inner surface. Silver ink is injected into the hole, which is made thoroughly conductive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a transparent touch panel substrate at once by using a specific transparent touch panel substrate mold.

[0002]

2. Description of the Related Art As a transparent touch panel, a PET (polyethylene terephthalate) film is used as a touch-side substrate (pressing side), a glass plate is used as a non-touch-side substrate (display side), and an IT is provided on each side.
There is a combination in which a resistance thin film is provided with O (indium oxide / tin) or the like, and the resistance thin film is arranged so as to face each other through an insulating spacer. Here, in order to derive an input current that is touch-input from the touch-side substrate and connect it to another circuit (for example, LCD), an FPC lead wire may be taken out from the side surface of the panel toward the outside.

The insulating spacers are minute protrusions for forming a minimum required distance in order to keep the touch-side substrate and the non-touch-side substrate completely insulated when no input (touch) operation is performed. Is. Therefore, the spacer is made of a transparent resin having high insulation and high hardness. The manufacturing method is generally a touch-side substrate provided with a resistance film made of ITO or the like, or a non-touch-side substrate surface, using a UV-curable acrylic resin, a desired shape by a printing method such as screen printing, After forming protrusions with the size and arrangement, they are exposed to ultraviolet rays to be cured and fixed to form spacers. The shape, size, and arrangement state of the spacers are various, but in general, the dots are 10 to 40 μm in diameter and 5 to 10 μm in height, and the spacers are arranged in a grid pattern at a pitch of about 0.5 to 4 mm.

Further, when the touch side substrate surface is touched (finger or pen) for input, in order to prevent a Newton's ring which is likely to appear around the touch point, the touch side substrate surface or the non-touch side substrate surface is Particle distribution of ~ 100μm by spray method etc. (eg 300-3000 particles / inch
² ) It is known that this is a problem.
-76118 publication.

Further, each of the substrates themselves is generally used by cutting it out from a raw material or a raw material into a desired size.

[0006]

Since the insulating spacer is manufactured by a printing method or a masking method, it is difficult to accurately and accurately form protrusions having a desired shape and size. This is because it is difficult to uniformly obtain the necessary space when the substrates are opposed to each other, and the appearance looks unpleasant, which is also a problem in terms of quality. Since the insulating spacer is different from the material of the substrate, improvement in transparency cannot be expected due to the difference in refractive index, and it acts in the direction of decrease. Furthermore, since another step is required for manufacturing, more attention is required in handling the step.

Further, when the inventors of the present invention retested the measures against the Newton's rings shown in the above-mentioned Japanese Patent Laid-Open Publication No. Sho, the occurrence of Newton's rings was certainly suppressed, but the transparency was tending to decrease. Further, fine particles of about 50 μm or more cause an extremely rough coating surface, which also causes a decline in the function of the touch panel. Furthermore, it was found that it is very difficult to coat the entire surface because of the need for a separate process of coating.

Further, the FPC lead wire drawn out from the side surface of the transparent touch panel has a problem that there is a risk of disconnection during handling and that it cannot be made compact because it takes up space.

Further, the glass substrate used as the non-touch substrate greatly reduces weight and ease of handling.

The present invention has been found as a result of intensive studies on the above problems. Therefore, the first object of the present invention is to manufacture a substrate for a transparent touch panel having an insulating spacer from the same material all at once. The second purpose is to manufacture the substrate having the spacer and the Newton's ring preventing means or the electrode drawing means all at once by using the same material, and the third purpose is to particularly the non-touch side. The glass plate that is the substrate of
Instead, it is to provide an all-plastic transparent touch panel that is lightweight and easy to handle.

[0011]

In order to achieve the first object, a transparent resin is injected and molded into a mold for a transparent touch panel substrate having a recess for an insulating spacer. Thus, the substrates having the same material and having the spacers having a constant shape and size arrangement can be manufactured all at once. This will be described in detail below.

First, a mold is required to manufacture a desired transparent touch panel substrate itself. The mold is basically composed of a cavitation (female) and a core (male), and a void is formed therein. Since the transparent touch panel substrate is manufactured by injecting the transparent resin into the void, basically, by changing the size of the void (length x width x depth), the touch side of the same size Alternatively, the non-touch side substrate can be manufactured. The size (vertical x horizontal) of the touch-side substrate and the non-touch-side substrate varies depending on the purpose and application, so the size of the void portion may be changed accordingly, but generally the thickness of the touch-side substrate is about 0. 1 to
Since it is 0.25 mm, and the non-touch side substrate is about 0.25 to 5 mm, the depth of the void portion may be determined based on this.
As described above, the size of each substrate (length x width x thickness)
Is basically determined by the size of the void, but resin generally has molding shrinkage, so it is desirable to design the mold in consideration of this. Further, the transparent touch panel substrate referred to here is a substrate on the touch side and / or the non-touch side.

After the size of the mold (gap) is determined, it is necessary to provide an insulating spacer recess on the upper or lower surface of the mold, that is, on the surface of the cavity or the core. The depression is not only a touch with a light pressure, but also a minute function that separates the resistive film surface on the touch side from the resistive film surface on the non-touch side to form a completely insulated state when no touch operation is performed. It is for forming protrusions (dots). Therefore, the function thereof is different from that of Newton's ring preventing fine unevenness described later. Therefore, it is generally provided with a larger number and a smaller number than the fine irregularities for prevention.

In order to most effectively exhibit the above-mentioned functions, it is desired that the recesses have the necessary minimum size, shape and arrangement. Therefore, the optimum condition may be determined by various examinations, and therefore, the shape is not fixed, but the shape is selected from, for example, a cubic shape, a rectangular shape, a conical or truncated conical shape, a prism, and a cylinder. The size is such that the recess entrance area is 8 × 10 ⁻⁵ to 8 ×
10 ⁻³ mm ² , preferably 3 × 10 ^{−4 to} 3 × 10 ⁻³ mm ² ,
The height is set to 5 to 20 μm, preferably 6 to 15 μm in the mold. Further, the number of the recesses according to these shapes and sizes is preferably the number provided so that the distance between the recesses is about 0.5 to 5 mm, preferably 1 to 4 mm.

Further, the arrangement state of the concave portions is preferably a regular arrangement such as a staggered shape or a lattice shape, rather than a random arrangement.

The size and shape of the above-mentioned recesses are as follows.
The explanation is given on the assumption that the insulating spacer formed by the recess is reproduced as it is (1: 1). Therefore, if the transparent resin contracts and falls out of the above range, it is necessary to correct it so that it enters and to provide the recess.

The method of producing the recess is generally performed by a die, that is, a method of producing a pattern or the like engraved on the inner surface of the cavitation or the inner surface of the core. That is, photoengraving / etching method,
By an electric discharge machining method using a mother die, an NC milling machining method, or the like. Among them, the photoengraving / etching method can surely produce even finer concave portions with good reproducibility.

Here, the photoengraving / etching method is a method in which a photosensitive agent is applied to the inner surface of the mold by coating or the like, and a negative or positive film having a desired dot pattern for an insulating spacer is masked to be exposed and developed. , Ferric chloride,
When the pattern is etched with an aqueous solution of nitric acid or the like for a predetermined time, the pattern becomes a recess and is reproduced. The height can be controlled by the etching time.

Although one mold may be used, it is preferable to provide a plurality of molds through a runner and mold a large number at a time. Further, either the movable side or the fixed side of the cavities and the core forming the mold may be either, but it is preferable that the cavities are the fixed side.

Using the mold thus obtained, a transparent resin is injected into the mold to integrally mold a substrate for a transparent touch panel with a desired insulating spacer. Here, the resin and the injection molding are as follows. is there.

First, the resin is a synthetic resin having excellent transparency and melting or softening at a predetermined temperature.
Here, the transparency has a smaller haze value (for example, 5% or less) as an essential condition for the touch panel substrate.
This means that the total light transmittance is higher (for example, 80% or more). Needless to say, it is also desirable that the strength, heat resistance, and chemical resistance are excellent, but the hardness is also high (for example, Rockwell hardness is 60 or more, preferably 70 or more).
Is preferred. It is desired that the hardness be higher, especially in the touch side substrate. This is to improve durability in the case of pen touch.

Therefore, any existing resin can be used as long as it satisfies the above conditions, but the following is given as an example. Amorphous polyester (for example, Eastman Chemical Company Easter), polymethylmethacrylate, polycarbonate, diethyleneglycolbisallylcarbonate, polystyrene, styrene / acrylonitrile copolymer, copolymer with styrene / methylmethacrylate, polyvinyl chloride , Polysulfone,
Examples thereof include polymethylpentene, an acryl-imide polymer (for example, Caymax manufactured by Sumika Hercules Co., PMI resin manufactured by Mitsubishi Rayon Co., Ltd.), and a blend polymer mainly composed of syndiotactic polypropylene. In the thermosetting resin, if there is one that meets the above conditions at the prepolymer stage, the resin can also be used, but in such a case, molding is performed by injecting into a mold at the prepolymer stage and performing post-curing. Needs heating.

The melting or softening of the resin is necessary for the present invention to adopt a molding method called injection molding. There are various molding methods other than injection molding, but this is not effective for molding with high precision and speed with a specific mold as in the present invention. There are no special conditions for this injection molding method, and it is based on a commonly used method. For example, if a non-touch side substrate is to be manufactured using polymethylmethacrylate, a mold in which a recess for an insulating spacer is provided on the cavity side is first attached to a screw type extruder. The resin pellets are vacuum dried at 80 to 95 ° C. for about 4 to 6 hours to completely remove water. Then, this is quantitatively supplied at a predetermined rate from the hopper of the extruder in which the barrel temperature of the extruder is adjusted to 220 to 270 ° C and the mold temperature is adjusted to 50 to 90 ° C. When the amount for molding the substrate is supplied, the substrate is stopped, cooled, and knocked out to automatically take out.

Of the above-mentioned resins, except for the blend polymer mainly composed of Syndiotac polypropylene, all are amorphous resins, so that the temperature of the mold is not particularly considered. In the case of a blended polymer, which is a crystalline resin, the transparency changes depending on the mold temperature. In such a case, the transparency is further improved by lowering the temperature and quenching.

In order to achieve the second object, the Newton's ring is formed in the mold for forming a void corresponding to the size of the transparent touch panel substrate, that is, on the surface of the cavity or the core together with the recess for the insulating spacer. A fine uneven portion for prevention or / and a core pin for an electrode lead-out hole are provided, and a transparent resin is injected and molded in the same as described above.

As described above, the Newton's ring has a stripe pattern due to light interference seen at the touch point. As a means for preventing this, in the present invention, an uneven portion is provided in the mold,
By molding, unevenness is formed at the same time when the substrate is molded.

Since the irregularities must have a content that exerts the function of preventing Newton's rings, in order to do so, it is necessary to provide an infinite number of minute irregularities that are much finer than the concave portions for insulating spacers. I can say. However,
If it is too fine and innumerable, there is a risk that the transparency will be deteriorated due to diffused reflection, so it is desired to form fine irregularities in an appropriate range.

The fine irregularities in the appropriate range have a cutoff value of 0.8 mm or less, preferably 0.08 to
It is within 0.25 μm and has a center line average roughness (Ra) of about 0.05 to 2 μm, preferably 0.1 to 1 μm.
Here, the cutoff value generally refers to the degree of surface waviness, but in the present invention it refers to the distance between the peaks and valleys or the valleys and valleys of the fine irregularities. As described above, such a range is provided in consideration of the effect of preventing the generation of Newton's rings as well as the effect of additional transparency, and it is preferable that the fine irregularities are too small and conversely too large. It is not a thing.

The Newton's ring preventing fine concavities and convexities formed on the transparent touch panel substrate are formed on the touch side and / or non-touch side substrate, but either one is preferable considering the influence on the transparency. . When the touch-side substrate is shaped, it may be shaped on both sides. This is because, in the case of both surfaces, one surface exerts a Newton's ring prevention function, but the other surface has a low light ray reflection effect, so that the surrounding objects often reflected on the touch surface are not reflected, and it is easier to see and operate.

As a means for producing fine unevenness for preventing Newton's rings in the mold, basically the method exemplified in the case of the recess for the insulating spacer can be used, but in the case of electric discharge machining, the mother die is photoengraved. -In the case of etching, it is necessary to change the pattern of the masking film to the unevenness for prevention. However, since the arrangement state and the shape do not necessarily have to be constant, it can be produced by the sandblast method.

The insulating spacer concave portion and the Newton's ring preventing fine concave-convex portion provided in the mold may be manufactured in either order, but preferably the concave-convex portion is formed first and the concave portion is formed later. Good.

On the other hand, in some cases, the recesses for insulating spacers and the core pins for electrode lead-out holes may be provided in the mold without providing the Newton's ring preventing concavo-convex portion. This is because depending on the surface characteristics of the transparent touch panel substrate and the size of the substrate, the Newton's ring that may cause a problem may not occur.

The electrode lead-out hole core pin is provided to make a hole in the peripheral portion of the transparent touch panel substrate. The hole is for drawing out an electrode provided in the transparent touch panel, so that the FP from the side surface of the panel, which is generally provided for drawing out the electrode, is formed.
The C lead is completely removed.

A predetermined number of the core pins are vertically provided on the peripheral portion of the cavity or the core of the mold. The perforation position is the peripheral part because the electrode part provided in the transparent touch panel is the peripheral part, and therefore the hole formed is the position where the electrode lead-out part exists. The number of the core pins is generally determined by the (function-based) method of the transparent touch panel. The method includes an analog method, a matrix method, and a combination method of both. For example, in the analog system, the touch-side and non-touch-side substrates require electrode holes of 2 holes (4 wire type) or 4 holes (8 wire type) respectively, so the core pin is 2 or 4 Need. In the matrix method, the holes are required for the number of strip-shaped resistance films, so that the core pins corresponding to the holes are vertically provided.
The shape of the core pin is generally a cylinder of about 1 to 3 mmφ, but it may be an ellipse, a prism, or the like.

The touch side or non-touch side transparent resin substrate obtained by injection molding with the mold provided with the core pin has a required number of holes, and the holes are made conductive to allow signal transmission. Wired to connect to the processing circuit. However, the holes can also be brought together on either the touch side or the non-touch side of the substrate, which is preferred in some cases. That is, for example, in the case of the analog system of the 4-wire type, four holes are provided in either one, and in the case of the 8-wire type, eight holes are provided in either one. Therefore, the number of core pins vertically provided in the mold is four or eight.

The holes provided in the substrate can be electrically connected to the electrode portions by injecting a conductive paste into the holes or by electroless plating with nickel or the like.

The most preferable embodiment of the present invention is a transparent touch panel substrate having a transparent resin, which has three functions of an insulating spacer, fine irregularities for preventing Newton's rings, and electrode lead-out holes (conduction holes) at the same time. It is to manufacture all at once by injection molding. Therefore, in such a case, the mold has a desired void, and the cavity or core surface is provided with the insulating spacer recessed portion, the Newton ring preventing concavo-convex portion, and the electrode lead-out core pin as described above. A transparent resin may be injected into the obtained mold and molded. In the case of having these three functions, the non-touch side substrate is preferable to the touch side substrate.

In the transparent touch panel substrate manufactured as described above, there is no Newton's ring preventing unevenness, there is no electrode drawing hole, and the substrate is either the touch side or the non-touch side. In some cases, there is only one. In such a case, a transparent touch panel substrate having the above-mentioned function is separately prepared by a method generally used in the past, and the transparent touch panel substrate is combined with any one of the substrates prepared according to the present invention. It can also be assembled and used as.

The transparent touch panel substrate is finally assembled as a transparent touch panel and framed by an aluminum chassis or the like. In order to fix the chassis to the chassis or the like at a fixed position quickly and surely. An edge is provided on the substrate, and a fixing means, for example, a mounting projection, is attached to the edge portion,
A hook for fixing by hooking, or a method for fixing the edge portion with an adhesive may be adopted. Of course, in the case of providing such fixing means, it is advisable to attach the fixing means to the mold and perform the injection molding at once.

[0040]

Since the transparent resin is injection-molded using the specific mold as described above, the refractive index is first the same,
Even if the insulating spacer concave portion and the Newton ring preventing fine concave-convex portion are provided, the transparency is not affected, or even if they are present, they are extremely small. Further, since the insulating spacers and the fine irregularities are provided by integral molding, they are not separated from the transparent touch panel substrate.

The Newton's ring, that is, the stripe pattern due to optical interference does not occur, because two or more waves (light) having an equal wavelength or a wavelength close to that at the touch point are scattered by the fine irregularities present at the touch point. It becomes light, and as a result, the waves do not overlap and do not interfere.

[0042]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Example 1 An iron-based cavitate having a depth of 3.0 mm, a length of 200 mm, and a width of 250 mm was prepared, and its inner surface was mirror-finished to have a Ra of 0.03 μm or less. Next, the mirror-finished surface was thinly coated with an acrylic photosensitive resin and dried to sensitize it. On the other hand, the area is 6.44 × 10 ^-4 mm ² (diameter about 30μ
m) a negative type flat net made by arranging circular halftone dots in a grid pattern at a pitch of 2.5 mm, vacuum-contacting this on the photosensitive surface of the cavitation and exposing it to ultraviolet light, and after alkali development Etching with an aqueous ferric chloride solution corroded the unexposed areas. The resist film was removed, washed thoroughly with water and dried. During the etching, sufficient care was taken to prevent the ferric chloride aqueous solution from contacting the surface other than the photosensitive film surface.

The uneven surface of the obtained cavities was recorded on a chart by a surface roughness measuring instrument (Curcom 570A type, manufactured by Tokyo Seimitsu Co., Ltd.). From this chart, the pitch is 2.48 mm and the diameter is about 30.2 μm arranged in a grid pattern.
In other words, it was possible to know the formation of a recess having a height of 11 μm and an entrance size of about 7 × 10 ⁻⁴ mm ² .

On the other hand, 1.0 in close contact with the cavitation.
mm Cavity depth 2.0 mm that can be crowned with the same material as the cavitation, center line surface roughness Ra 0.03 μm
It was made with a mirror finish so that

A transparent resin gate, a projecting pin, and an air vent were provided in the cavitation, and the cavity was set at the tip of an injection molding machine together with the core, and a non-touch side substrate was prepared under the following conditions. Using sufficiently dried bisphenol aromatic polycarbonate pellets as a transparent resin, barrel temperature of 260 to 300 ° C., mold (the cavitation and core)
The temperature was adjusted to 100 ° C. and 100 sheets were injection molded. The obtained molded product has a thickness of 1.98 mm and a length of 199.1.
It was a transparent and rigid polycarbonate sheet (hereinafter PC sheet) having a width of 24 mm and a width of 249.3 mm.

Three of the obtained PC sheets were sampled, and the convex surface on which each sample was formed was measured by the surface roughness profiler and recorded on a chart. From the height of this chart, 10.5-10.7 μm, diameter 29.
2 to 29.6 μm (area about 6.7 × 10 ^{−4 to} 6.9 × 1)
0 ^-4 mm ^2), it was confirmed that projections of the pitch distance between 2.47mm are arranged in a grid pattern. This indicates that it is formed as a protrusion having substantially the same shape and size as the recess formed in the cavitation. It should be noted that the surface on which the convex portion was formed and the surface of the conventional product were compared and observed with the naked eye, but the presence of the protrusion was not noticeable. This is different from the insulating spacer formed by the conventional method (different material and method), and is formed integrally with the same material, and because it is made regularly with the same shape and size, the It is probable that it was not visible because there was no dynamic reflection.

Example 2 The same cavity as that used in Example 1 was prepared, and a Newton ring preventing concavo-convex portion and an insulating spacer concave portion were formed by the following means. First, a mirror-finished surface of the cavitation was thinly coated with an acrylic photosensitive resin and dried to sensitize it. Then, a 600-line flat screen positive film made of circular dots was vacuum-adhered to the photosensitive surface, exposed to ultraviolet rays, developed with alkali, and etched with an aqueous ferric chloride solution. Finally, the resist film was removed, washed thoroughly with water and dried. At the time of etching, sufficient care was taken so that the ferric chloride aqueous solution did not come into contact with anything other than the photosensitive film surface.

The surface of the obtained cavitation was measured by a surface roughness profile measuring instrument, Surcom 570A (manufactured by Tokyo Seimitsu Co., Ltd.), and it was found that Ra at a cutoff value of 0.08 mm.
It was 1.01 to 1.12 μm. The fine irregularities obtained here have the function of preventing Newton's rings at the time of touch.

Then, an acrylic photosensitive resin was coated again on the finely textured surface of the obtained cavitation in the same manner as described above and dried to sensitize it. Then, the negative type flat screen used in Example 1 was vacuum-adhered to this photosensitive surface, and UV exposure, alkali development, and ferric chloride etching were sequentially performed,
Finally, the resist film was removed, washed with water and dried. In this case as well, in the etching as well, sufficient care was taken to prevent others from being etched.

The surface of the obtained cavitation was measured again by the above-mentioned surface roughness measuring instrument and recorded on a chart.
From this chart, the diameters of the diameters 30.
It was confirmed that a recess having a size of ⁴ μm (area of about 7.4 × 10 ⁻⁴ mm ² ) and a height of 14 μm was formed. This cavitation is hereinafter referred to as NS cavitation.

A transparent resin gate, a projecting pin, and an air vent were provided on the cavity NS, and the core used in Example 1 was combined with this to form a die, and a substrate on the non-touch side was formed under the following conditions. The mold was set at the tip of the injection molding machine, the barrel temperature of the molding machine was controlled at 90 to 120 ° C, and the mold was controlled at 40 ° C. A sufficiently dried amorphous polyester (Easter / PETG) pellet was supplied and molded to obtain 100 substrates. The thickness of this molded substrate is 1.99 mm, length 198.9 mm, width 249.8 mm.
It was a rigid and rigid polyester sheet, and the fine irregularities and protrusions formed on the surface were hard to see with the naked eye. Hereinafter, the sheet is referred to as an A / PET sheet.

Three A.PET sheets were sampled, each sample was measured by the surface roughness profiler, and recorded on a chart. From this chart, the cutoff is 0.08 mm, Ra is 0.98 to 1.10 μm, the fine irregularities, the height is 13.6 to 13.9 μm, and the diameter is 30.1.
~ 30.3 µm (area about 6.1 x 10 ^{-4 to} 7.2 x 10
It was confirmed that the protrusions of ^-4 mm ² ) were shaped like a lattice.

Example 3 The cavitation NS used in Example 2 had a height of 3.
4 stainless steel core pins with a diameter of 5 mm and a diameter of 1.5 mm
It was vertically fixed in a side-by-side arrangement with a pitch of 3 mm around the side. As the core for this, the core used in Example 2 was used as it was to form a pair of molds. Further, the core is provided with receiving holes so that the tips of the four core pins can be easily inserted and removed. FIG. 1 is a side sectional view showing this mold in the drawing.
In the figure, reference numeral 1 is a cavitation, on the inner surface of which fine Newton ring preventing fine concavities and convexities 2 are provided, recesses for insulating spacers 3 and four core pins 6 are provided. Reference numeral 4 is a core, and an imaginary drawing is 5 when the core is separated from the cavitation 1. Reference numeral 7 is a receiving hole at the tip of the core pin 6.

Next, the mold shown in FIG. 1 was set at the tip of the injection molding machine and molded under the following conditions. The sufficiently dried polymethylmethacrylate pellets are heated to a barrel temperature of 220 to
It was injected into the hopper of the molding machine controlled at 260 ° C. and the mold temperature of 65 ° C. for injection molding. Molding was completed after obtaining 100 molded sheets. The obtained molded sheet had a thickness of 1.97 mm, a length of 199.0 mm, and a width of 249.5 mm, and the surface was visually inspected, but it was also difficult to see fine projections and depressions. The sheet had four through holes each having a diameter of 1.49 mm.

Then, three of the above-mentioned molded sheets were sampled and the surface was measured with a surface roughness profile measuring instrument, Surcom 570A type. From the obtained chart, a cut-off value of 0.08 mm, Ra 1.01 to 1.12 μm of fine unevenness, a height of 13.3 to 13.7 μm, and a diameter of 29.9 to 3
0.0 μm (area about 7 × 10 ^{−4 to} 7.1 × 10 ⁻⁴ mm ² )
It was confirmed that the protrusions of No. 3 were formed in a grid pattern at a pitch of 2.91 to 3.0 mm.

Finally, a touch panel was produced using the above-mentioned molded sheet, and the effects of each of the shaped Newton ring preventing fine concavities and convexities, the insulating spacer, and the electrode lead-out hole were confirmed as follows.

First, the necessary touch panel was manufactured as follows. The polymethylmethacrylate molded sheet was used as the non-touch side substrate, and ITO was sputtered on the imprinted surface.
A TO resistance film was provided. However, at the time of this sputtering, the 1.5 mm width around the sheet was first masked so as not to be sputtered, and the electrode lead-out hole was masked so that only the hole was sputtered and did not conduct to other resistance films. Sputtering was performed.

Next, since the ITO resistance film is attached to the projections for the insulating spacer by the sputtering,
It needs to be removed. Therefore, I took the following method. An acrylic resin solution (40%) dissolved in ethyl cellosolve acetate was used as the ITO of the substrate.
The entire resistance film was coated and heated to evaporate the solvent to form a 5 μm acrylic resin film. And the thickness of the surface wetting with ethyl cellosolve acetate 1.1mm
The glass plate of 3 was placed on the resin film surface and held for 1.5 minutes, and then the glass plate was immediately removed. Then, the substrate is 25
% Hydrochloric acid aqueous solution for 1.5 minutes and washed with water. Finally, it was immersed in ethyl cellosolve acetate to dissolve and remove all the resin films. As a result of observing the obtained substrate with an optical microscope, only the ITO resistance film at the tip portion (about half) of the protrusion for insulating spacer was removed, and other ITO resistance films were not affected at all.

Further, silver ink was screen-printed from both sides of the ITO resistance film of the substrate to provide electrode lines, which were drawn out and their terminals were connected to two holes.

On the other hand, the touch side substrate has a thickness of 188 μm.
A PET film having a length of m, a length of 199.0 mm and a width of 249.5 mm was prepared, and ITO was sputtered on one surface of the PET film to form an ITO resistance film of 500 angstrom. Also during this sputtering, a mask having a width of 15 mm was used to prevent the ITO resistance film from being attached. Then, an electrode wire was drawn out from this ITO resistance film with silver ink as described above, and its terminal was provided so as to be aligned with the remaining two holes.

The resistance film surfaces of the respective substrates are opposed to each other,
A touch panel was obtained by adhesively fixing it with an insulating tape having a thickness of 20 μm and a width of 3 mm. Incidentally, here, silver ink was injected into the four holes so that they were each electrically connected to the resistance film.

The structure of the touch panel will be described in detail with reference to the side sectional view of FIG. In the figure, 9 is a non-touch side substrate made of polymethylmethacrylate, and the inner surface of the substrate 9 has fine unevenness 10 for preventing Newton's rings and projections 1 for insulating spacers, which are formed by molding at once.
1 and 4 electrode drawing holes 14, 16, 18, 2
There is 0, and silver ink is injected into the hole so that it is completely conductive. Of course, the surface of the fine unevenness 10 is made of ITO.
A resistance film is formed. Electrode wires (silver ink) drawn out from both sides of the resistance film are provided as indicated by 13 and 19, and their terminals are connected to the conduction holes 14 and 20.

The opposing touch-side substrate is 12 PE.
It is made of T film, and the ITO resistance film 21 is formed on the inner surface.
Electrode wires (silver ink) drawn out from both sides of the resistance film are provided as 15 and 17, and the terminals are located in the conduction holes 16 and 18.

Reference numerals 14 and 20, 16 and 18 are conductive holes in the non-touch side and touch side substrates, respectively, which are filled with silver ink and connected to the terminals of the electrode lines. Both substrates are adhesively fixed via 22 insulating tapes. It should be noted that although the drawing shows that there is a void portion, this is merely shown for convenience of explanation of the structure of the inner surface, and in reality, the insulating spacer 11 is used.
The gap is the same as or slightly higher than the height of.

Next, whether the transparent touch panel shown in FIG. 2 operates normally is checked. First, the resistance value is checked by the tester through the conduction hole, and after confirming that there is no problem, the LCD is processed through the signal processing circuit. By connecting with (LCD display), various information was touch-input with a pen. As a result, the LCD screen was displayed according to the input information. Moreover, the Newton ring phenomenon was not observed at all.

[0066]

Since the present invention is configured as described above, it has the following effects.

The insulating spacer concave portion or the transparent touch panel substrate on which the concave portion and the fine irregularities for preventing Newton's rings are formed by injection molding of a transparent resin into a mold all at once, so that the quality is always high. The stable and desired substrate can be obtained quickly and efficiently.

Since both the insulating spacer and the fine unevenness for preventing Newton's rings are integrally formed in the same material, the transparency of the whole is hardly deteriorated by this.

Since there is no generation of Newton's ring, that is, optical interference fringes observed at the time of touch input, there is no troublesome operation or quality trouble.

Further, a hole for drawing out an electrode can be provided in the substrate at the same time as the injection molding by vertically arranging a core pin for forming the hole in the mold. This does not require the work of drilling a hole separately, and has a wiring structure for connecting the hole that has been conducted to an interface board or LCD, so take out the FPC lead wire from the side surface of the transparent touch panel so far. It is not necessary to have a wiring structure for connecting this to the interface board or the like.

As a result of taking the above wiring structure, F
The risk of wire breakage during handling of the touch panel, which is seen in PC lead wires, is eliminated, and even if the touch panel itself breaks down or becomes unusable due to its life, it can be easily replaced by a new one.

Generally, the steps of separately cutting each substrate and forming the insulating spacers and the Newton's ring preventing concavities and convexities are completed in one step at the same time by injection molding with a mold, so that the time required for the conventional separate steps can be reduced. On the other hand, it not only significantly shortens the time, but also has a great effect in terms of equipment and production control.

[Brief description of drawings]

FIG. 1 is a side sectional view of a mold.

FIG. 2 is a side sectional view of a transparent touch panel.

[Explanation of symbols]

 1 Cavitation (Example 3) 2 Concavities and convexities for preventing Newton's rings 3 Recesses for insulating spacers 4 Cores 5 Cores away from cavities (imaginary figure) 6 Core pins 7 Core pin receiving holes 8 Voids 9 Polymethylmethacrylate substrate 10 ITO resistance Fine unevenness with film 11 Insulation spacer 12 PET substrate 13 Electrode wire 14 Conduction hole 15 Electrode wire 16 Conduction hole 17 Electrode wire 18 Conduction hole 19 Electrode wire 20 Conduction hole 21 ITO resistance film 22 Insulation tape

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Murakami 163 Morikawahara-cho, Moriyama-shi, Shiga Gunze Stock Company Development Department Electronic Functional Materials Center

Claims (4)

[Claims] 1. A method of manufacturing a substrate for a transparent touch panel, which comprises injecting and molding a transparent resin into a mold for a transparent touch panel substrate having a recess for an insulating spacer. 2. A transparent resin is injected and molded into a mold for a transparent touch panel substrate provided with a recess for an insulating spacer and a fine uneven portion for preventing Newton's rings or / and a core pin for an electrode drawing hole. A method for manufacturing a substrate for a transparent touch panel. 3. The entrance area of the recess for the insulating spacer is 8 × 10.
-5 to 8 x 10 ^-3 mm ² , height is ⁵ to 20 µm, and the pitch between the concave portions is 0.5 to ⁵ mm, and the production of the transparent touch panel substrate according to claim 1 or 2. Method. 4. A fine uneven portion for preventing Newton's rings has a cutoff value of 0.8 mm or less and a center line average roughness of 0.05 to 2 μm.
The method for manufacturing a substrate for a transparent touch panel according to claim 2, wherein the substrate has a myriad of fine irregularities made of m.